For a single snake owner, it would be really great to see the system be able to grow with the snake by being able to accommodate multiple sizes of tubs in the same rack. That is, it would be nice to buy say a 70 sized rack that comes with 20/40/70 tubs (selectable by the buyer) and swap in bigger ones as your snake grows instead of having to repurchase the rack part multiple times. But, their tubs vary in height slightly which messes with this. 20=5", 40=5.5", 70=5.25".